This invention relates to paper honeycomb cushioning pads having improved energy absorbing properties.
In recent years, paper honeycomb has come into widespread use as a cushioning material for dissipating the energy released upon impact of a moving object with another moving or stationary object or with the ground. The Armed Forces have adopted airdrop delivery, preferably from low-flying aircraft, as one method of distributing supplies to troops in the field. Heavy equipment is also being delivered by airdrop at points where it is urgently needed. Usually supplies or equipment are lashed to a rigid platform or pallet for this purpose. Parachutes are employed to reduce the velocities of the loaded pallets. However, the shock of landing must be absorbed in some manner so that as little damage as possible will be done to the supplies or equipment. This is done either by fastening paper honeycomb cushioning pads to the underside of the pallet or by interposing such pads between the pallet and the equipment or supplies lashed to the pallet.
It has been found that when heavy loads cushioned by means of paper honeycomb pads landed, quite often a blowout occurred at one or both of the ends of many of the cushioning pads. The ends are normal to the glue lines that cement the sheets of paper together forming hexagonally shaped cells in the expanded paper honeycomb. A blowout usually begins by separation of the glue lines nearest to an end of the pad and progresses inwardly of the pad as failure of successive glue lines occurs. Such blowouts result in rather wide variations in the impact strengths of similarly prepared paper honeycomb cushioning pads of the prior art.
It is, therefore, an object of the invention to provide paper honeycomb cushioning pads having improved impact strengths.
A further object of the invention is a substantial reduction of blowouts of paper honeycomb cushioning pads so that such pads will accomplish the maximum possible energy absorption when crushed by impact.
Other objects and advantages of the invention will be apparent from the following description of the invention, and the novel features will be particularly pointed out hereinafter in connection with the appended claims.